JPH0377583B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a loading drive mechanism for a magnetic recording/reproducing device.

[Background of the invention]

A differential speed reduction mechanism is known as a loading drive mechanism for a conventional magnetic recording/reproducing device, and this is shown in FIG.

There is a pair of planetary gears 2 and 3 meshing with a sun gear 1 connected to a drive source (not shown), and an internal gear 4 meshing with the planetary gears 2 and 3. A plurality of protrusions 4a are formed on the outer periphery of the internal gear 4. A similar protrusion 5a is also formed on the outer periphery of a rotatable disc 5 coaxial with the sun gear 1. These protrusions 4a, 5a are alternately prevented from rotating by claws 7a, 7b which are oscillated by the plunger 6. In the illustrated state, the pawl 7a prevents the protrusion 4a from moving, thereby preventing the internal gear 4 from rotating.

When the sun gear 1 connected to the drive source rotates,
The planetary gears 2 and 3 roll inside an internal gear 4, and a disk 5 supports the shafts of these planetary gears 2 and 3.
rotates, and this rotation is used for cassette loading, etc. On the other hand, when the plunger 6 swings the pawl clockwise, the pawl 7b stops the rotation of the disc 5 to prevent the projection 5a from moving, and as a result, the planetary gears 2 and 3 rotate and the internal gear 1 rotates, and this is used for tape loading, etc.

In this manner, the conventional loading mechanism uses not only a driving source for the sun gear 1 but also the pawl 7 in order to perform cassette loading and tape loading.
A plunger 6, which is a separate drive source for switching between a and 7b, is required, which increases the size and complicates the structure.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a loading drive mechanism for a magnetic recording/reproducing device that is compact without using a separate drive source.

[Summary of the invention]

The present invention relates to a disk rotatably supporting two planetary gears disposed around a sun gear connected to a drive source, an internal gear meshing with these planetary gears, and the disk and the internal gear. and a pawl device that alternately engages with engaging portions formed on the respective sides, and selectively transmits the driving force from the driving source as the rotational force of the internal gear and the rotational force of the disc, and A driving force is applied to a loading mechanism connected to each of the internal gear and the disc, and the disc and the internal gear are rotated when their engaging portions are released from the pawl device. In the loading drive mechanism of the magnetic recording/reproducing device, when one of the engaging portions of the pawl device is engaged, either an internal gear or a disk having the other engaging portion rotates, and the pawl device rotates. It is characterized in that the pawl device is configured to be released from one engaging portion.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 1 is a sectional view, and FIG. 2 is a plan view thereof. A rotating member 22, which includes a wheel 22a and a sun gear 22b coaxially integrally formed, is rotatably fitted to a shaft 21 established in the chassis 20. The wheel 22a meshes with a worm 23 that is connected to a motor or the like as a drive source (not shown) via a transmission means such as a belt 24. A pair of shafts 26a and 26b are established in a disc 25 rotatably disposed on the upper surface of the rotating member 22, and planetary gears 27a and 27b are rotatably fitted to these shafts, respectively. Further, the planetary gears 27a and 27b mesh with the sun gear 22b. Furthermore, a protrusion 2 formed above the sun gear 22b of the rotating member 22
An internal gear 28 is rotatably mounted on 2c.
This internal gear 28 meshes with the previous planetary gears 27a and 27b. Further, a stop pin 29 is embedded in the outer periphery of the lower surface of the internal gear 28. An outer claw 30 and an inner claw 31 are attached to a sub-chassis 32 fixed to the chassis 20, the details of which will be described later.

With such a configuration, when the rotating member 22 is rotated by the drive source, if the position of the disk 25 is fixed, the internal gear 28 will rotate due to the rotation of the planetary gears 27a and 27b. On the other hand, internal gear 2
If 8 is fixed, planetary gears 27a, 27b
The disc 25 rotates via the.

FIG. 3 is an exploded perspective view of the loading drive mechanism shown in FIGS. An outer claw 30 is rotatably fitted. The outer claw 30 is elastically held in the state shown in FIG. 4 by a torsion spring 33. Further, a pin 36 is established in the sub-chassis 32 at a position corresponding to the pin 29 of the internal gear 28, and the internal pawl 31 is rotatably fitted into this pin 36. The inner claw 31 is elastically held in the state shown in FIG. 4 by a torsion spring 34. Furthermore, the sub chassis 32 has a claw 3.
Stoppers 37 and 38 for 0 and 31 are formed. In this way, the sub chassis 32 has two
Two claw devices are constructed.

Next, the function of the pawl device will be explained using FIGS. 4 to 9.

In FIG. 4, the internal gear 28 includes a gear portion and a pin 2.
Only 9 is shown. Sun gear 22 driven by a driving source
The rotation in the direction of arrow a of b is caused by planetary gears 27a and 27b.
An attempt is made to rotate the disc 25 in the direction of arrow b to rotate the disc 25 counterclockwise, but since the inner claw 31 is engaged with the protrusion 25a of the disc 25, the disc 25 does not rotate. , the internal gear 28 meshing with the planetary gears 27a and 27b rotates clockwise. When the internal gear 28 represented by the pin 29 rotates in the same direction, the pin 29 moves in the direction of arrow c, rotates the external pawl 30 counterclockwise, pushes it away, and hits the internal pawl 31 as shown in FIG. This will apply a clockwise rotational force. For this reason, the engagement between the protrusion 25a of the disc 25 and the inner claw 31 is disengaged, and when the pin 29 moves through the angle Θ shown in FIG. 4, the inner claw 31 is stopped from rotating clockwise by the stopper 38. At the same time, clockwise rotation of the internal gear 28 is also prevented.

Further, when the sun gear 22b is rotated in the same direction by the driving source, the planetary gears 27a and 27b revolve around the shaft 21 while rotating in the b direction as shown in FIG. d counterclockwise. In this way, the disk 25 can be rotated through an angle Θ ₁ .

Next, a case will be described in which the sun gear 22b is rotated in the opposite clockwise direction by the drive source.

The planetary gears 27a and 27b rotate in the direction of the arrow as shown in FIG. 7, and since the pin 29 is prevented from rotating counterclockwise by the external pawl 30, the disk 25 rotates in the clockwise direction of the arrow. Rotate by an angle Θ ₂ .
When rotated by an angle Θ ₂ , the protrusion 25a is rotated by the outer claw 30.
The outer pawl 30 is allowed to rotate counterclockwise by a predetermined angle by the stopper 37 as shown in FIG. Prevents clockwise rotation. Therefore, the planetary gears 27a and 27b are prevented from rotating around the shaft 21, and the internal gear 28 can now be rotated counterclockwise within the range of angle Θ ₃ as shown in FIG.

As can be seen from the above description, the external pawl 30 allows the internal gear 28 to rotate clockwise and prevents it from rotating counterclockwise, and also prevents the disk 25 from rotating clockwise. On the other hand, the internal claw 31 is connected to the internal gear 28.
Clockwise rotation is prevented, and counterclockwise rotation of the disk 25 is prevented. The engagement for preventing the counterclockwise rotation of the disk 25 by the inner claw 31 is released by the pin 29 of the internal gear 28, and the engagement for preventing the counterclockwise rotation of the pin 29 by the outer claw 30 is released. Since the pin 29 and the protrusion 25a are combined so as to be released by the protrusion 25a, there is no need to provide a separate drive source for the pawl device. The rotation can be used for tape loading and other purposes.

Next, the deceleration effect will be explained. sun gear 22
The number of teeth of b is Z _A , the number of teeth of planetary gears 27a and 27b is Z _B , and the gear of internal gear 28 is Z _C , sun gear 22b
When the rotation speed of the internal gear 28 is N _A , the rotation speed of the internal gear 28 is N _C
(1) When the rotation of the disc 25 is restricted by the internal pawl 31, N _C =N _A・Z _A /Z _C ... (1), (2) When the internal gear 28 is restricted from rotating by the external pawl 31 The rotational speed N _D of the disc 25 when its rotation is regulated by is N _D =N _A ·Z _A /Z _C /1+Z _A /Z _C (2).

In this way, the internal gear 28 is reduced in speed relative to the sun gear 22b by the gear ratio thereof, and in the case of the disc 25, the speed is further reduced. Regarding the transmitted torque,
This is an increase by the reciprocal of each reduction ratio.

The main parts of the magnetic recording and reproducing apparatus using the loading drive mechanism of the above-described embodiment are shown in FIGS. 10 and 1.
Shown in Figure 1.

Gear parts are also formed on the outer peripheral surfaces of the disc 25 and the internal gear 28, and follower gears 40, 41 are formed opposite to each gear part.
The follower gear 40 can be connected to a tape loading mechanism, and the follower gear 41 can be connected to a cassette loading mechanism. A cam 42 is provided on the upper surface of the internal gear 28, and the rotation of the cam 42 is converted into a rocking motion via a lever 43. By providing a plurality of such cams and levers, the pinch roller, brake and tension Can be used for arm loading.

In the above embodiment, the disc 25 and the internal gear 28, which are rotated alternately by the sun gear 22b, which is a gear unit connected to a drive source, each have a protrusion 25
a and a stopper pin 29, and these protrusions 25
a and the stopper pin 29 are alternately engaged by the pawl device, but the shape can be used without any limitation, and in the end, the disc 25 and the internal gear 28 are released by the pawl device. It suffices if each of them has an engaging portion that can be engaged with each other. Further, the pawl device may be configured to obtain a releasing force for each engaging portion when the other engaging portion is engaged, and various shapes and structures can be adopted.

〔Effect of the invention〕

As explained above, in the present invention, engaging portions are formed in each of the disc and the internal gear constituting the differential speed reduction mechanism, and the pawl device that alternately engages these engaging portions is configured to When engaged, the other engaging part rotates to release the pawl device from one engaging part, so there is no need to provide a separate drive source exclusively for the pawl device. A compact loading drive mechanism can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a loading drive mechanism of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. 3 is an exploded perspective view of FIG. 1. 4 to 9 are plan views for explaining the operation, respectively. FIG. 10 is a front view of the main part of a magnetic recording and reproducing apparatus using the loading drive mechanism shown in FIG. FIG. 12 is a perspective view of essential parts and a plan view showing a conventional loading drive mechanism. 21... Shaft, 22... Rotating member, 22b... Sun gear, 25... Disc, 25a... Protrusion, 27
a, 27b... Planetary gear, 28... Internal gear, 29
...stopper pin, 30...inner claw, 31...outer claw.

Claims (1)

[Claims] 1. A disk rotatably supporting two planetary gears arranged around a sun gear connected to a drive source, an internal gear meshing with these planetary gears, and a disk formed on the disk and internal gear, respectively. and a pawl device that alternately engages with the engaging portion, and selectively transmits the driving force from the drive source as the rotational force of the internal gear and the rotational force of the disk, and A driving force is applied to a loading mechanism connected to each of the discs, and the discs and the internal gear are rotated when their engaging portions are released from the pawl device. In the loading drive mechanism of the device,
In the pawl device, when one of the engaging portions is engaged, either an internal gear or a disc having the other engaging portion rotates to release the pawl device from the one engaging portion. A loading drive mechanism for a magnetic recording/reproducing device, characterized in that it is configured to.